8 inch pipeline

8" pipeline in the Gulf of Mexico retrofit with anode strings and RetroClamp™ system

Deepwater Corrosion Services was contracted by Chevron to provide cathodic protection (CP) retrofit materials for their 8” wet oil pipeline running from their fixed jacked platform to shore. Low CP readings had been reported by a third-party surveying company. To increase the CP protection, Deepwater supervised as divers attached two RetroLink™ anode strings to the pipeline using a RetroClamp™.

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Retroclamp info

Results

The RetroClamp™ was installed on the pipeline and continuity was checked between the RetroClamp™ and pipeline using Deepwater’s diver-held Polatrak® CP Gun™. Once continuity was confirmed, RetroLinks™ were lowered into position. The RetroLinks™ were attached to the RetroClamp™ and continuity was checked using Deepwater’s diver-held CP Gun™. Once it was confirmed that the RetroLinks™ were continuous with the pipeline, the RetroLinks™ were jetted into the mud and the RetroClamp™ and RetroLinks were sandbagged to protect against trawling. After the installation was complete, the Deepwater technician performed a CP survey at the riser where the 8” pipeline leaves the platform. The pre-retrofit CP reading on the pipeline was -0.818V vs silver / silver chloride (Ag/AgCl) electrode, and the CP readings after the RetroLinks™ were installed and buried was -0.998V vs silver / silver chloride (Ag/AgCl) electrode. This provided a negative potential shift of 180mV.